Integrated control of nitrate recirculation and external carbon addition in a predenitrification system

The integrated control of nitrate recirculation and external carbon addition in a predenitrification biological wastewater treatment system is studied. The proposed control structure consists of four feedback control loops, which manipulate the nitrate recirculation and the carbon dosage flows in a highly coordinated manner such that the consumption of external carbon is minimised while the nitrate discharge limits (based on both grab and composite samples) are met. The control system requires the measurement of the nitrate concentrations at the end of both the anoxic and the aerobic zones. Distinct from ordinary control systems, which typically minimise the variation in the controlled variables, the proposed control system essentially maximises the diurnal variation of the effluent nitrate concentration and through this maximises the use of influent COD for denitrification, thus minimising the requirement for external carbon source. Simulation studies using a commonly accepted simulation benchmark show that the controlled system consistently achieves the designated effluent quality with minimum costs.

Combining nonthermal technologies to control foodborne microorganisms

Novel nonthermal processes, such as high hydrostatic pressure (HHP), pulsed electric fields (PEFs), ionizing radiation and ultrasonication, are able to inactivate microorganisms at ambient or sublethal temperatures. Many of these processes require very high treatment intensities, however, to achieve adequate microbial destruction in low-acid foods. Combining nonthermal processes with conventional preservation methods enhances their antimicrobial effect so that lower process intensities can be used. Combining two or more nonthermal processes can also enhance microbial inactivation and allow the use of lower individual treatment intensities. For conventional preservation treatments, optimal microbial control is achieved through the hurdle concept, with synergistic effects resulting from different components of the microbial cell being targeted simultaneously. The mechanisms of inactivation by nonthermal processes are still unclear; thus, the bases of synergistic combinations remain speculative. This paper reviews literature on the antimicrobial efficiencies of nonthermal processes combined with conventional and novel nonthermal technologies. Where possible, the proposed mechanisms of synergy is mentioned. (C) 2003 Elsevier Science B.V. All rights reserved.

A role for pectin in the control of cell expansion

Uptake of nutrients and water depends on the growth of roots through elongation of individual cells near the. root tip. Many of the numerous components of Type I primary cell walls, those of dicotyledons and monocotyledons other than grasses (Poaceae), have been determined, and many hypotheses have been proposed for the control of cell expansion. This important aspect of plant growth still needs elucidation, however. A model is proposed in which pectin, which occurs as a calcium (Ca) pectate gel between the load-bearing cellulose microfibrils and xyloglucan (XG) chains, controls the rate at which cells expand. It is considered that the increasing tension generated by the expanding cell is transmitted to interlocked XG chains and cellulose microfibrils. The resulting deformation of the embedded Ca pectate gel elicits the excretion of protons from the cytoplasm, possibly via compounds such as cell wall-associated kinases, that weakens the Ca pectate gel, permitting slippage of XG molecules through the action of expansin. Further slippage is prevented by deformation of the pectic gel, proton diffusion, and the transfer of residual tension to adjacent XG chains. Evidence for this model is based on the effects of pH, Ca, and aluminum (Al) on root elongation and on the reactions of these cations with Ca pectate. This model allows for genetic selection of plants and adaptation of individual plants to root environmental conditions.

Digitally-implemented naturally sampled PWM suitable for multilevel converter control

For dynamic closed loop control of a multilevel converter with a low pulse number (ratio of switching frequency to synthesized fundamental), natural sampled pulse-width modulation (PWM) is the best form of modulation. Natural sampling does not introduce distortion or a delayed response to the modulating signal. However previous natural sampled PWM implementations have generally been analog. For a modular multilevel converter, a digital implementation has advantages of accuracy and flexibility. Re-sampled uniform PWM is a novel digital modulation technique which approaches the performance of natural PWM. Both hardware and software implementations for a five level multilevel converter phase are presented, demonstrating the improvement over uniform PWM.

O combate ?? viol??ncia contra a mulher: a luta entre antigos valores e novos padr??es de pol??ticas p??blicas

O caso relata uma situa????o de viol??ncia dom??stica vivenciada por uma mulher negra e os obst??culos por ela enfrentados para denunciar o agressor e fazer valer seus direitos. Mostra a contradi????o entre normas e sua efetiva aplica????o, quando o comportamento de agentes p??blicos ainda conserva padr??es e valores de um Estado autorit??rio, patriarcal e escravocrata. O caso ?? fict??cio, mas espelha situa????es reais coletadas em documentos e relat??rios da Ouvidoria da Secretaria de Pol??ticas para as Mulheres- SPM/PR. O estudo suscita discuss??es sobre a dimens??o ??tica da atividade de agentes p??blicos de um Estado democr??tico, englobando quest??es referentes aos direitos humanos, direitos e deveres do Estado e da sociedade, o papel da transpar??ncia, do controle social e da responsabiliza????o por resultados (accountability) etc. Pode ser aplicado em cursos sobre ??tica e servi??o p??blico, pol??ticas p??blicas de g??nero e ra??a e atendimento ao cidad??o

Percepção dos agentes comunitários de saúde frente ao risco de infecção da tuberculose

A Tuberculose é um serio problema de saúde, os níveis mundiais no ano 2011 ocorreram 8,7 milhões de casos novos e 1,4 milhões de pessoas morreram de TB. Para horizontalizar as ações no combate da TB na atenção primaria o Agente Comunitário de Saúde assume um papel muito importante, pois eles além de trabalhar na comunidade onde mora ele é um mediador de saberes, espera-se que esse profissional seja capaz de identificar por meio de visitas domiciliares sintomáticos respiratórios. Objetivos: Conhecer a percepção que os ACS têm sobre o risco de infecção à tuberculose no cotidiano de sua prática profissional e analisar como eles se organizam e estruturam sua prática frente a essa percepção. Abordagem Metodológica: O estudo foi dividido em duas fases a primeira responde ao primer objetivo e foi escolhido o Grupo Focal e para a segunda fase que responde ao segundo objetivo foi escolhido a Observação Participante como técnicas de trabalho em campo e Analise de Conteúdo Temático como técnica de análise das informações colhidas que consiste em descobrir os núcleos de sentidos que são temas os quais são unidades de significação que se libertam naturalmente de um texto analisado. Resultados: Na primeira fase do estudo observou-se que o Agente Comunitário de Saúde percebe os riscos que estão expostos, mas muitas vezes eles não sabem como agir em situações, especificas, na segunda fase indicam que o risco não esta presente o tempo todo na vida e no trabalho deles. Conclusão: O PACS é apresentado pelo Ministério da Saúde como uma estratégia de saúde para horizontalizar as ações no controle da TB, neste estudo foi encontrado que o ACS percebe o risco que esta exposto, mas que aquele risco não esta sempre presenta na vida deles, pois eles muitas vezes minimizam os riscos pensando que nada acontece nem acontecera com eles.

Chemical treatment of papaya seeds aiming at long-term storage and control of damping off

Damping off is a nursery disease of great economic importance in papaya and seed treatment may be an effective measure to control. The aim of this work was to evaluate the quality of papaya seeds treated with fungicides and stored under two environmental and packaging conditions. Additionally, the efficiency of fungicide treatments in the control of damping-off caused by Rhizoctonia solani was evaluated. Papaya seeds were treated with the fungicides Captan, Tolylfluanid and the mixture Tolylfluanid + Captan (all commercial wettable powder formulations). Seeds of the control group were not treated. The seeds were stored for nine months in two conditions: packed in aluminum coated paper and kept at 7 ± 1ºC and in permeable kraft paper and kept in non-controlled environment. At the beginning of the storage and every three months the seed quality (germination and vigor tests), emergence rate index, height, dry mass and damping of plants in pre and post-emergence (in contaminated substrate and mycelia-free substrate) were analyzed. Both storage conditions as well as the fungicide treatments preserved the germination and seed vigor. In the infested substrate, seedling emergence was favored by fungicides, but in post-emergence, fungicides alone did not control the damping off caused by R. solani. Symptoms of damping off were not observed in the clean substrate. The results showed that the fungicide treatments may be used to pretreat papaya seed for long-term storage and commercialization.

Automation & control remote laboratory: evaluating a cooperative methodology

This paper presents a study carried out in order to evaluate the students' perception in the development and use of remote Control and Automation education kits developed by two Universities. Three projects, based on real world environments, were implemented, being local and remotely operated. Students implemented the kits using the theoretical and practical knowledge, being the teachers a catalyst in the learning process. When kits were operational, end-user students got acquainted to the kits in the course curricula units. It is the author's believe that successful results were achieved not only in the learning progress on the Automation and Control fields (hard skills) but also on the development of the students soft skills, leading to encouraging and rewarding goals, motivating their future decisions and promoting synergies in their work. The design of learning experimental kits by students, under teacher supervision, for future use in course curricula by enduser students is an advantageous and rewarding experience.

Silicon in plant disease control

All essential nutrients can affect the incidence and severity of plant diseases. Although silicon (Si) is not considered as an essential nutrient for plants, it stands out for its potential to decrease disease intensity in many crops. The mechanism of Si action in plant resistance is still unclear. Si deposition in plant cell walls raised the hypothesis of a possible physical barrier to pathogen penetration. However, the increased activity of phenolic compounds, polyphenol oxidases and peroxidases in plants treated with Si demonstrates the involvement of this element in the induction of plant defense responses. The studies examined in this review address the role of Si in disease control and the possible mechanisms involved in the mode of Si action in disease resistance in plants.

Postharvest biological control of brown rot in peaches after cold storage preceded by preharvest chemical control 1

ABSTRACT Pathogenic fungi cause skin darkening and peach quality depreciation in post harvest. Therefore, alternative techniques to chemical treatment are necessary in order to reduce risks to human health. The aim of this study was to evaluate the effect of the application of Trichoderma harzianum in association with different fungicides applied before harvest to 'Eldorado' peaches for brown rot control and other quality parameters during storage. The treatments consisted of five preharvest fungicide applications (control, captan, iprodione, iminoctadine and tebuconazole) associated with postharvest application of T. harzianum, after cold storage (with and without application), in three evaluation times (zero, two and four days at 20 °C), resulting in a 5x2x3 factorial design. The application of T. harzianum only brought benefits to the control of brown rot when combined with the fungicide captan, at zero day shelf life. After two days, there was a greater skin darkening in peaches treated with T. harzianum compared with peaches without the treatment, except for peaches treated with the fungicide iprodione and T. harzianum The application of T. harzianum during postharvest showed no benefits for the control of brown rot, however, the association with fungicides reduced the incidence of Rhizopus stolonifer during the shelf life.

IDENTIFYING ETHICAL DILEMMAS OF PORTUGUESE CHARTERED ACCOUNTANTS

The way professionals deal with ethical dilemmas and the decisions they make may be guided by a personal and individual ideology, but it is also strongly influenced by their professional group and society. This paper focuses in real situations as they are experienced by individuals in their day-to-day professional life. The data were collected using opened-end interviews. Respondents were asked to identify the ethical dilemmas they had been faced with during their professional life. Qualitative analysis shows that main dilemmas are about how to deal with “informal economy”, “false invoices” and “tax evasion”. This study aims to contribute to the discussion of ethical issues faced by Portuguese Chartered Account (TOC), thus promoting a large debate about the way the TOC can help to create a better society and consequently legitimating their existence as a professional organization of public interest. More than ever, understanding professionals’ behavior in their real context is essential for to build a culture conducive to the ethical development of society, and to ensure, at the same time, the desirable business sustainability. This study gives a broaden description of ethics dilemmas faced by chartered accounts and shows some inefficiency in the ethical control system made by professional bodies.